K does not show function signature

Question

My full config is on GitHub.

In my lsp-config.lua I have the following:

buf_set_keymap('n', 'K', '<cmd>lua vim.lsp.buf.hover()<CR>', opts)

However, when I press K on the name of a function, nothing happens. Also, when I run :map! K I get:

No mapping found

What am I doing wrong?

I want to know what the function signature on NewGoFunction is so that I can better understand what it expects.

UPDATE

I've just realised that some other key bindings aren't working either. For example I have:

buf_set_keymap('n', '[d', '<cmd>lua vim.lsp.diagnostic.goto_prev()<CR>', opts)

But when I press that, I get:

E388: Could not find definition

So it is trying to go to definition for some reason!

I'm really confused.

MORE INFO

I am using gopls as the language server for LSP. Here is the output of :LspInfo

Answer 1

Use this for gopls server:

nvim_lsp.gopls.setup {
  cmd = {"gopls", "serve"},
  on_attach = on_attach,
  capabilities = capabilities,
  settings = {
    gopls = {
      analyses = {
        unusedparams = true,
      },
      staticcheck = true,
    },
  },
}

In your lsp config, you had the following:

local servers = { 'clangd', 'rust_analyzer', 'pyright', 'tsserver', 'elmls' }
for _, lsp in ipairs(servers) do
  nvim_lsp[lsp].setup {
    on_attach = on_attach,
    capabilities = capabilities,
  }
end

nvim_lsp.gopls.setup {
  cmd = {"gopls", "serve"},
  on_attach = on_attach,
  capabilities = capabilities,
  settings = {
    gopls = {
      analyses = {
        unusedparams = true,
      },
      staticcheck = true,
    },
  },
}

Notice that you had a for loop for assigning on_attach and capabilities for all servers in the list/table servers.

But you forgot to add gopls to your servers list, so the on_attach (which contains the keymaps) wasn't assigned to the proper function.